MultiTech / libxDot-dev-mbed5-deprecated

Bleeding edge development version of the xDot library for mbed 5. This version of the library is not guaranteed to be stable or well tested and should not be used in production or deployment scenarios.

Dependents:   Dot-Examples Dot-AT-Firmware Dot-Examples TEST_FF1705 ... more

The Dot library provides a LoRaWan certified stack for LoRa communication using MultiTech mDot and xDot devices. The stack is compatible with mbed 5.

Dot Library Version 3 Updates

Dot Library versions 3.x.x require a channel plan to be injected into the stack. Channel plans are included with the 3.x.x Dot Library releases. The following code snippet demonstrates how to create a channel plan and inject it into the stack.

#include "mDot.h"
#include "channel_plans.h"

int main() {
    ChannelPlan* plan = new lora::ChannelPlan_US915();
    assert(plan);
    mDot* dot = mDot::getInstance(plan);
    assert(dot);

    // ...
}

Dot devices must not be deployed with software using a different channel plan than the Dot's default plan! This functionality is for development and testing only!

Multicast Sessions

Multicast sessions and packet rx events in library. When in Class C mode Multicast downlinks can be received. Recieved packets should be filtered on address, counter value will be maintained in the session or can be set explicitly depending on Application support to share Multicast Address, Keys and Counters.

mDot.h

        /**
         * Add a multicast session address and keys
         * Downlink counter is set to 0
         * Up to 3 MULTICAST_SESSIONS can be set
         */
        int32_t setMulticastSession(uint8_t index, uint32_t addr, const uint8_t* nsk, const uint8_t* dsk);
 
        /**
         * Set a multicast session counter
         * Up to 3 MULTICAST_SESSIONS can be set
         */
        int32_t setMulticastDownlinkCounter(uint8_t index, uint32_t count);

mDotEvent.h

The address field was added to PacketRx event.

        virtual void PacketRx(uint8_t port, uint8_t *payload, uint16_t size, int16_t rssi, int8_t snr, lora::DownlinkControl ctrl, uint8_t slot, uint8_t retries, uint32_t address);

The name of the repository can be used to determine which device the stack was compiled for and if it's a development or production-ready build:

A changelog for the Dot library can be found here.

The Dot library version and the version of mbed-os it was compiled against can both be found in the commit message for that revision of the Dot library. Building your application with the same version of mbed-os as what was used to build the Dot library is highly recommended!

The Dot-Examples repository demonstrates how to use the Dot library in a custom application.

The mDot and xDot platform pages have lots of platform specific information and document potential issues, gotchas, etc, and provide instructions for getting started with development. Please take a look at the platform page before starting development as they should answer many questions you will have.

Diff: plans/ChannelPlan_AS923.cpp

Revision:
121:b7c80d8c4eb2
Parent:
120:77af6791e600
Child:
126:c17213d3156d
--- a/plans/ChannelPlan_AS923.cpp	Tue Aug 14 15:45:14 2018 -0500
+++ b/plans/ChannelPlan_AS923.cpp	Thu Aug 30 09:06:17 2018 -0500
@@ -92,6 +92,12 @@
 
     GetSettings()->Session.Rx2Frequency = 923200000;
     GetSettings()->Session.Rx2DatarateIndex = DR_2;
+
+    GetSettings()->Session.BeaconFrequency = AS923_BEACON_FREQ;
+    GetSettings()->Session.BeaconDatarateIndex = AS923_BEACON_DR;
+    GetSettings()->Session.PingSlotFrequency = AS923_BEACON_FREQ;
+    GetSettings()->Session.PingSlotDatarateIndex = AS923_BEACON_DR;
+
     GetSettings()->Session.Max_EIRP  = 16;
 
     logInfo("Initialize datarates...");
@@ -271,7 +277,7 @@
     return LORA_OK;
 }
 
-uint8_t ChannelPlan_AS923::SetRxConfig(uint8_t window, bool continuous) {
+uint8_t ChannelPlan_AS923::SetRxConfig(uint8_t window, bool continuous, uint16_t wnd_growth) {
 
     RxWindow rxw = GetRxWindow(window);
 
@@ -285,8 +291,10 @@
     uint32_t sf = rxDr.SpreadingFactor;
     uint8_t cr = rxDr.Coderate;
     uint8_t pl = rxDr.PreambleLength;
-    uint16_t sto = rxDr.SymbolTimeout();
+    uint16_t sto = rxDr.SymbolTimeout() * wnd_growth;
     uint32_t afc = 0;
+    bool fixLen = false;
+    uint8_t payloadLen = 0U;
     bool crc = false; // downlink does not use CRC according to LORAWAN
 
     if (GetSettings()->Network.DisableCRC == true)
@@ -299,6 +307,14 @@
         iq = txDr.TxIQ;
     }
 
+    // Beacon modifications - no I/Q inversion, fixed length rx, preamble
+    if (window == RX_BEACON) {
+        iq = txDr.TxIQ;
+        fixLen = true;
+        payloadLen = sizeof(BCNPayload);
+        pl = BEACON_PREAMBLE_LENGTH;
+    }
+
     SxRadio::RadioModems_t modem = SxRadio::MODEM_LORA;
 
     if (sf == SF_FSK) {
@@ -315,7 +331,7 @@
     // logTrace("Configure radio for RX%d on freq: %lu", window, rxw.Frequency);
     // logTrace("RX SF: %u BW: %u CR: %u PL: %u STO: %u CRC: %d IQ: %d", sf, bw, cr, pl, sto, crc, iq);
 
-    GetRadio()->SetRxConfig(modem, bw, sf, cr, afc, pl, sto, false, 0, crc, false, 0, iq, continuous);
+    GetRadio()->SetRxConfig(modem, bw, sf, cr, afc, pl, sto, fixLen, payloadLen, crc, false, 0, iq, continuous);
 
     return LORA_OK;
 }
@@ -375,7 +391,9 @@
         rxw.Frequency = GetSettings()->Network.TxFrequency;
         index = GetSettings()->Session.TxDatarate;
     } else {
-        if (window == 1) {
+        switch (window) {
+        case RX_1:
+        {
             // Use same frequency as TX
             rxw.Frequency = _channels[_txChannel].Frequency;
 
@@ -392,8 +410,21 @@
             uint8_t minDr = GetSettings()->Session.DownlinkDwelltime == 1 ? 2 : 0;
             index = std::min<uint8_t>(5, std::max<uint8_t>(minDr, index));
 
-        } else {
-            // Use session RX2 frequency
+            break;
+        }
+
+        case RX_BEACON:
+            rxw.Frequency = GetSettings()->Session.BeaconFrequency;
+            index = GetSettings()->Session.BeaconDatarateIndex;
+            break;
+
+        case RX_SLOT:
+            rxw.Frequency = GetSettings()->Session.PingSlotFrequency;
+            index = GetSettings()->Session.PingSlotDatarateIndex;
+            break;
+
+        // RX2, RXC, RX_TEST, etc..
+        default:
             rxw.Frequency = GetSettings()->Session.Rx2Frequency;
             index = GetSettings()->Session.Rx2DatarateIndex;
         }
@@ -492,54 +523,67 @@
 }
 
 uint8_t ChannelPlan_AS923::HandlePingSlotChannelReq(const uint8_t* payload, uint8_t index, uint8_t size, uint8_t& status) {
+    uint8_t datarate = 0;
+    uint32_t freq = 0;
 
-    lora::CopyFreqtoInt(payload + index, _beaconRxChannel.Frequency);
-    index += 3;
+    status = 0x03;
 
-    if (_beaconRxChannel.Frequency != 0) {
-        _beaconRxChannel.DrRange.Value = payload[index];
-    } else {
-        // TODO: set to default beacon rx channel
+    freq = payload[index++];
+    freq |= payload[index++] << 8;
+    freq |= payload[index++] << 16;
+    freq *= 100;
+
+    datarate = payload[index] & 0x0F;
+
+    if (freq == 0U) {
+        logInfo("Received request to reset ping slot frequency to default");
+        freq = AS923_BEACON_FREQ;
+    } else if (!CheckRfFrequency(freq)) {
+        logInfo("Freq KO");
+        status &= 0xFE; // Channel frequency KO
     }
 
-    status = 0x03;
+    if (datarate < _minRx2Datarate || datarate > _maxRx2Datarate) {
+        logInfo("DR KO");
+        status &= 0xFD; // Datarate KO
+    }
+
+    if ((status & 0x03) == 0x03) {
+        logInfo("PingSlotChannelReq accepted DR: %d Freq: %d", datarate, freq);
+        GetSettings()->Session.PingSlotFrequency = freq;
+        GetSettings()->Session.PingSlotDatarateIndex = datarate;
+    } else {
+        logInfo("PingSlotChannelReq rejected DR: %d Freq: %d", datarate, freq);
+    }
+
     return LORA_OK;
 }
 
 uint8_t ChannelPlan_AS923::HandleBeaconFrequencyReq(const uint8_t* payload, uint8_t index, uint8_t size, uint8_t& status) {
+    uint32_t freq = 0;
 
-    status = 0x03;
-    Channel chParam;
+    status = 0x01;
 
-    // Skip channel index
-    index++;
+    freq = payload[index++];
+    freq |= payload[index++] << 8;
+    freq |= payload[index] << 16;
+    freq *= 100;
 
-    lora::CopyFreqtoInt(payload + index, chParam.Frequency);
-    index += 3;
-    chParam.DrRange.Value = payload[index++];
-
-    if (!GetRadio()->CheckRfFrequency(chParam.Frequency)) {
+    if (freq == 0U) {
+        logInfo("Received request to reset beacon frequency to default");
+        freq = AS923_BEACON_FREQ;
+    } else if (!CheckRfFrequency(freq)) {
+        logInfo("Freq KO");
         status &= 0xFE; // Channel frequency KO
     }
 
-    if (chParam.DrRange.Fields.Min < chParam.DrRange.Fields.Max) {
-        status &= 0xFD; // Datarate range KO
-    } else if (chParam.DrRange.Fields.Min < _minDatarate || chParam.DrRange.Fields.Min > _maxDatarate) {
-        status &= 0xFD; // Datarate range KO
-    } else if (chParam.DrRange.Fields.Max < _minDatarate || chParam.DrRange.Fields.Max > _maxDatarate) {
-        status &= 0xFD; // Datarate range KO
+    if (status & 0x01) {
+        logInfo("BeaconFrequencyReq accepted Freq: %d", freq);
+        GetSettings()->Session.BeaconFrequency = freq;
+    } else {
+        logInfo("BeaconFrequencyReq rejected Freq: %d", freq);
     }
 
-    if ((status & 0x03) == 0x03) {
-        _beaconChannel = chParam;
-    }
-
-    if (_beaconChannel.Frequency == 0) {
-        // TODO: Set to default
-    }
-
-    status = 0x01;
-
     return LORA_OK;
 }
 
@@ -1045,3 +1089,39 @@
     }
 }
 
+bool ChannelPlan_AS923::DecodeBeacon(const uint8_t* payload, size_t size, BeaconData_t& data) {
+    uint16_t crc1, crc1_rx, crc2, crc2_rx;
+    const BCNPayload* beacon = (const BCNPayload*)payload;
+
+    // First check the size of the packet
+    if (size != sizeof(BCNPayload))
+        return false;
+
+    // Next we verify the CRCs are correct
+    crc1 = CRC16(beacon->RFU, sizeof(beacon->RFU) + sizeof(beacon->Time));
+    memcpy((uint8_t*)&crc1_rx, beacon->CRC1, sizeof(uint16_t));
+
+    if (crc1 != crc1_rx)
+        return false;
+
+    crc2 = CRC16(beacon->GwSpecific, sizeof(beacon->GwSpecific));
+    memcpy((uint8_t*)&crc2_rx, beacon->CRC2, sizeof(uint16_t));
+
+    if (crc2 != crc2_rx)
+        return false;
+
+    // Now that we have confirmed this packet is a beacon, parse and complete the output struct
+    memcpy(&data.Time, beacon->Time, sizeof(beacon->Time));
+    data.InfoDesc = beacon->GwSpecific[0];
+
+    // Update the GPS fields if we have a gps info descriptor
+    if (data.InfoDesc == GPS_FIRST_ANTENNA ||
+        data.InfoDesc == GPS_SECOND_ANTENNA ||
+        data.InfoDesc == GPS_THIRD_ANTENNA) {
+        // Latitude and Longitude 3 bytes in length
+        memcpy(&data.Latitude, &beacon->GwSpecific[1], 3);
+        memcpy(&data.Longitude, &beacon->GwSpecific[4], 3);
+    }
+
+    return true;
+}